Al-Khwarizmi

Muhammad ibn Musa al-Khwarizmi was born about the year 780, of the land of Khwarazm south of the Aral Sea — today divided across Uzbekistan and Turkmenistan. He came of age as the House of Wisdom rose in Baghdad, the great library and academy of the Abbasid caliphate, and it was there, around the year 820, that he did the work that would set the thought of the world in order for a thousand years.

His treatise on al-jabr wa’l-muqabala — “restoration and balancing” — was the first to treat algebra as a discipline in its own right, laying down systematic methods for solving linear and quadratic equations. From its title came the word algebra; from a Latin rendering of his own name came the word algorithm. He did not merely solve problems — he built the grammar by which anyone could solve them.

He carried the decimal, place-value numerals of India into the mathematics of the wider world; when his arithmetic reached Latin in the twelfth century, it taught Europe to reckon with the nine figures and the zero we still use. He composed the Zij al-Sindhind, tables of the heavens by which astronomers found the positions of stars and the timing of eclipses, and in his Book of the Description of the Earth he corrected Ptolemy’s map, fixing the coordinates of more than two thousand cities and places.

He died about the year 850. What he left was not a single discovery but a method — a way of setting knowledge in order so it could be taught, checked, and carried on. Every calculation a machine performs today still bears his name. Honored among the Great Ones of every civilization; kept here so the memory is never lost.